In mining operations, especially underground mining operations, such as coal mining or the like, conveyors or a series of conveyors are often used to transport the mined material out of the mine. Typically, there is a main conveyor that moves the mined material along a fixed path. Such main conveyor has a terminal end at a fixed location for receiving the material being transported out of the mine.
In the past, shuttle cars or other short distance haulage vehicles have been used to transport the mined material from the mining machine to the fixed terminal end of the main conveyor. The use of shuttle cars and other such haulage vehicles is, at best, intermittent, time consuming, and inefficient. Thus, in more recent years, there have been several developments directed toward the use of a mobile articulated conveyor system. In contrast to shuttle cars, a mobile articulated conveyor system provides for continuous transport of the mined material produced by a continuous mining machine along a conveyor as the continuous mining machine both advances into the mine face and changes the direction of its forward movement. Mobile articulated conveyor systems are particularly adaptable to "room and pillar" type coal mining operations, wherein the mobile articulated conveyor system follows the continuous mining machine and changes the direction of its travel as the continuous mining machine penetrates into the mine face in one room and then is backed out and set to work at the mine face in another room.
An early example of an articulated conveyor system appears in U.S. Pat. No. 4,332,317 (Bahre, et al.) assigned to Klockner-Werke AG of Duisburg, Germany. This early patent describes an articulated conveyor system for use in mining operations that can actually be moved within the mine to be near the mine face. But, the articulated conveyor system described in U.S. Pat. No. 4,332,317 cannot be automatically repositioned within the mine while the chain conveyor for moving mined material is actually moving the mined material out of the mine. Thus, the described articulated conveyor system described in U.S. Pat. No. 4,332,317 is incapable of remote operation.
U.S. Pat. No. 4,773,528 (Anderson, et al.) and U.S. Pat. No. 4,365,185 (Bodiner) assigned to Joy Technologies of Pittsburgh, Pa. describe an articulated conveyor system which can be repositioned within the mine at the same time a continuous conveyor belt is moving mined material out of the mine. The movement of the entire articulated conveyor system within the mine is facilitated by a plurality of framework members located under the continuous conveyor belt. Accordingly, the articulated conveyor system may be remotely operated. Steering of the articulated conveyor system is accomplished by the use of wheels on the input end of the conveyor system. In practice, it has been found that the inherent design and use of conveyor belt described in these two patents limits the total length of the articulated conveyor system to about 550 feet. Additionally, the length of the described conveyor system is limited as the tramming system described in U.S. Pat. Nos. 4,773,528 and 4,365,185 has difficulty negotiating multiple curves.
U.S. Pat. No. 5,096,048 (Lachner, et al.) assigned to Klockner-Becorit of Castrop-Rauxel, Germany is similar to U.S. Pat. No. 4,332,317, described above, in that the articulated conveyor system cannot be repositioned within the mine while the chain conveyor--for moving mined material--is actually moving mined material out of the mine. Movement of the articulated conveyor system within the mine is accomplished by dropping the chain conveyor down to the mine floor and then using the lower flight of the mined material movement chain as a tramming chain. Steering cylinders, located horizontally between separable segments of the conveyor support elements, allow the described articulated conveyor system to follow a path toward the mine face when the articulated conveyor system is repositioned within the mine.
U.S. Pat. No. 5,129,502 (Justice) assigned to Coaltex of Beckley, W. Va. describes a self-propelled articulated conveyor system. Mined material is moved away from the mine face through a tube by a long, continuous system of articulated augers. Repositioning or tramming of the entire articulated conveyor system within the mine is accomplished by the engagement of a conventional mining conveyor chain having transverse articulation interconnections between links with the mine floor. These transverse articulation interconnections allow the entire articulated conveyor system to follow a non-linear or curved pathway. The long, continuous system of articulating augers which is mounted over the conventional mining conveyor chain tramming system prohibits the use of the described system in thin coal seams; however, the entire articulated conveyor system can be moved to follow the mine face at the same time mined material is being taken out of the mine.
U.S. Pat. No. 5,634,545 (Plumley) assigned to Fairchild International of Glen Lyn, Va. describes a mobile articulated conveyor system in which a system of chain conveyor bridge sections are alternately placed on crawler-driven conveyor sections which engage the mine floor. The described articulated mobile conveyor system is designed to follow a continuous mining machine in room-and-pillar type mine configurations. The complex nature of the movement of the entire conveyor system requires that several operators in the mine to orchestrate the movements of the system to both position and re-position the bridge conveyor sections with respect to the crawler-driven chain conveyor sections.
Despite the improvements in mobile articulated conveyor systems described by the foregoing patents, a need still remains in the art for a mobile articulated conveyor system that is: a) capable of remote operation; b) will support the operation of a continuous miner in mines having thin seams of material; and c) is capable of conveying mined material while tramming or being repositioned to follow an active mine face. In addition, there is a need for a mobile articulated conveyor system: d) that is not length-limited; e) that can negotiate difficult steering patterns in underground mines; f) that can be easily converted from underground use to ground-level use; and g) that can be separated into individual sections to facilitate relocation and storage.